HSF advice for socket 754

My new mother board should be here soon and I've decided to upgrade my HSF. I'm leaning toward the Zalman CNPS7000 series as they are supposed to be quiet, cool very well, and appear to be easy to mount. The 7000A is a good unit, but Zalmans website says the 7000B is better. The 7000A seems to be readily available whereas the 7000B is hard to find. Quietpc has the 7000B-AlCu for $39.95 but I don't know anything about how reputable the company is.
The 7000B-Cu version weighs 755g vs. the 7000B-AlCu versions 438g. How big is the difference in cooling from all Cu to AlCu? Am I correct that weight is more of an issue in a tower than a desktop? Is the weight enough to worry about? Is the better cooling more important than the reduced weight?
So far I have not been overclocking, I don't do Lan parties, the only moving around is when I'm installing new components. Any insight about these HSFs and where to buy is appreciated. If you think I'm barking up a wrong tree and should go a different route that info will be appreciated as well; At this time I am on a budget and am not looking at liquid cooling as a viable option.

 

http://www.thermalright.com/

thermalright is the way to go ... id go w/ this:

http://www.sidewindercomputers.com/thxpforinp4.html

but make sure it is compatible with your motherboard ... otherwise go with this:

http://www.sidewindercomputers.com/thxpforforin.html

 

I like the Thermalrights, but had dismissed them because of weight. The first one you list with the fan they suggest weighs 640g. The second the heat sink alone is 360g and the website says "with a fan, the XP-90 still comes in well below the stock intel retail package weight of 450g" they then go on to list the specs for the suggested fan including the weight listed as 110g. I don't know modern math but when I went to school 360 + 110> 450.
Now I don't know if 470g is that big a deal considering I don't pack it around like a notebook. I'm a little concerned with how well a heat pipe based heat sink works in a tower orientation.

 

the zalman AICu is 445g ... i've been told the thermalrights work as good as water cooling and you can put any fan there you want ... but if you like the AICu that is still a good hsf

 

thanks for the input ~Pyrate~.